The Principal Investigator and associates have demonstrated that Plasmodium falciparum, growing in vitro in a Trager-Jensen culture system, is sensitive to exceedingly small concentrations of desferrioxamine (DF), a specific iron chelating agent, despite the large quantity of iron available to the intraerythrocytic malarial parasite in the form of hemoglobin. Thus the mechanism of iron acquisition by the malaris parasite is delicate and readily disrupted. That mechanism is of intrinsic biologic interest, but equally important, its elucidation may facilitate a new approach to therapy. The continual emergence of drug resistant malaria throughout the world makes the availability of new therapeutic approaches an important practical concern. Our specific aims are to study iron uptake by P. falciparum from transferrin, hemoglobin and ferritin and to study the distribution of that iron in the parasitizedd red call.